Distributors - options?

[Geoff-R]

Rebuilding my engine and my old distributor is knackered, well more specifically the vacuum advance is seized solid and well past it's use by date. I'm struggling to find a new one and although a punt on a second hand distributor with a vacuum advance on might be a 50:50 shot at whether it works for the long run is another question.

What are my options really? It's for an L26. Ideally standard would do me but should I be looking at something else? Opinions and suggestions welcome, cheers.

 

[jonbills]

I'd think the options are:
Adapt a new non datsun vacuum advance unit.
Go without vacuum advance, maybe just increase static advance a little and remove some mechanical advance to correct
Buy a 280zx dizzy (new/recon)
Buy the 123nl distributor like Ali and peato40.

I think they're the basic options.

 

[uk66fastback]

Following this as interested in what the options are for my standard L24 ...

 

[AliK]

So ...

This is where my adventures began too.

Bought a reman Cardone 280zx dizzy as my vac advance no longer worked and the bushes were worn causing a little side to side shaft movement.

THE CARDONE WAS A PIECE OF DUNG for £170 delivered cost. The shaft bushing was in a worse state than mine, the bearings were notchy as hell but it had a working vac canister.

I should have reined it but figured it would make good spares when I revise it myself someday. I took the vac canister out and replaced the one in my original dizzy - old one was properly lodged with corrosion so had to butcher it out!!!!

Cardone supplied vac advance was going 25 degrees (!!!!) but by taking the blob of epoxy off the end and adjusting the screw I have it down to about 12-14 degrees. I have discovered a couple of sites that sell a vac canister for other Nissan dizzies that appear to be the right size but I didn't investigate further. If you really want to go that route I could find it again. They are coming in at £60 ish from the US + delivery.

I bought the 123 ignition one for £400 which is a VERY impressive bit of kit but having unrelated electrical issues so can't fully comment but it is a fully programmable Bluetooth linked dizzy (read define our own curve and vac advance settings) which also acts as immobiliser and rev limiter.

My advice after seeing it working properly is that it is essential for a street car, cooler idle, fuel economy and responsiveness.

 

[jonbills]

I don't think I'd agree its essential, with a little modification to the mechanical advance you only notice the absence of vac advance in the economy.
Even then, on a motorway run I'm getting 30mpg without it.

 

[AliK]

And that debate rattles on in many forums Jon [emoji6]

Each to their own on this topic.

Racers don't use / need it as they are WOT or off throttle for 99% of the time.

The simple argument that I buy is that without it, there is no load sensing or adjustments based on engine load and the timing is purely base + mech.

Too much base and you risk pinking / detonation when mech comes in. Without altering the springs in the dizzy you can't change mech advance or its max rpm - so while yes, absolutely you can run without it, it's a compromise on a street car.

The quality of idle and fast idle (especially around town or roundabouts at 2krpm) on my engine is noticeably better with it connected. Also I find the transition from cruising to accelerating is much smoother.

.a great article here ...
http://www.superchevy.com/how-to/ad...now-about-vacuum-advance-and-ignition-timing/

 

[AliK]

Oh and another fun debate here ...

https://www.pistonheads.com/gassing/topic.asp?h=0&f=81&t=680424

 

[Alphabettispaghetti]

i'm going to leave this here

https://www.rhdjapan.com/kameari-l-...gnition-control-kit-with-spindle-gear-l6.html

I've resisted for days Ali

 

[Woody928]

And that debate rattles on in many forums Jon [emoji6]

Each to their own on this topic.

Racers don't use / need it as they are WOT or off throttle for 99% of the time.

The simple argument that I buy is that without it, there is no load sensing or adjustments base on engine load and the timing is purely base + mech.

Too much base and you risk pinking / detonation when mech comes in. Without altering the springs in the dizzy you can't change mech advance or its max rpm - so while yes, absolutely you can run without it, it's a compromise on a street car.

The quality of idle and fast idle (especially around town or roundabouts at 2krpm) on my engine is noticeably better with it connected. Also I find the transition from cruising to accelerating is much smoother.

.a great article here ...
http://www.superchevy.com/how-to/ad...now-about-vacuum-advance-and-ignition-timing/

How is it that you've successfully managed to persuade me that I need something that I didn't think I did.... It's way down the list but boy is it on there now!

 

[AliK]

How is it that you've successfully managed to persuade me that I need something that I didn't think I did.... It's way down the list but boy is it on there now!

Sadly my friend Mr Franky does that to me on a weekly basis - welcome to the club brah! [emoji6]

 

[Geoff-R]

The 123 ignition distributor looks like the most future proof set up if I'm honest. Pardon the ignorance but what alternations need to be made to the ignition system in order to run it?

 

[jonbills]

And that debate rattles on in many forums Jon [emoji6]

Each to their own on this topic.

Racers don't use / need it as they are WOT or off throttle for 99% of the time.

The simple argument that I buy is that without it, there is no load sensing or adjustments based on engine load and the timing is purely base + mech.

Too much base and you risk pinking / detonation when mech comes in. Without altering the springs in the dizzy you can't change mech advance or its max rpm - so while yes, absolutely you can run without it, it's a compromise on a street car.

The quality of idle and fast idle (especially around town or roundabouts at 2krpm) on my engine is noticeably better with it connected. Also I find the transition from cruising to accelerating is much smoother.

.a great article here ...
http://www.superchevy.com/how-to/ad...now-about-vacuum-advance-and-ignition-timing/

I don't think "essential" and "each to their own" are compatible opinions on this Ali [emoji6]
When *you* run without vacuum connected, you've got stock mechanical advance and that's not what I'm advocating.
At 1100 rpm, my car without vac already has about 28 deg advance so it picks up fine.
Come along to japshow at santa pod and we'll see who's dizzy works best [emoji4]

 

[AliK]

You definitely have the bigger one Jon

28 at 1100 is huge! How did you avoid pinking / knock!? Is it as simple as you never drive under 2000rpm? Or have a super wild cam and that helps drop the dynamic compression enough? Or is it the type of head / chambers you have that can cope with it?

Geoff - there is absolutely nothing to modify for 123. It's a bolt in job. It has three wires rather than 2 as it needs it's own ground, which you can take from the body if you wish. You can wrap the wires up with the existing loom and it looks it was always there (if you take off the Bluetooth label of course)!

The only time consuming thing is getting the engine bang on compression TDC on cyl 1 means taking the plugs out and rotating the engine by hand.

 

[jonbills]

You definitely have the bigger one Jon

28 at 1100 is huge! How did you avoid pinking / knock!? Is it as simple as you never drive under 2000rpm? Or have a super wild cam and that helps drop the dynamic compression enough? Or is it the type of head / chambers you have that can cope with it?

Geoff - there is absolutely nothing to modify for 123. It's a bolt in job. It has three wires rather than 2 as it needs it's own ground, which you can take from the body if you wish. You can wrap the wires up with the existing loom and it looks it was always there (if you take off the Bluetooth label of course)!

The only time consuming thing is getting the engine bang on compression TDC on cyl 1 means taking the plugs out and rotating the engine by hand.

I don't have any pinking that's for sure. Although my head and cam are good in this regard, I ran a lot of static advance on my old head and cam without trouble too - pinking is only a problem when you get much nearer the peak torque revs.

 

[AliK]

Good to know Jon. I'm constantly learning on this topic / new obsession!

 

[AliK]

Ps. Full write up on the 123 dizzy to follow when I'm trough my electrical problems and can subject it to a full test.

 

[uk66fastback]

Ps. Full write up on the 123 dizzy to follow when I'm trough my electrical problems and can subject it to a full test.

If you are getting one, where are you getting it - direct from 123 in The Netherlands? I was having a read about them last night. Undecided about getting one or just going with the the straight Pertronix/Flamethrower coil swap realise they're different things completely ...)

Good to know Jon. I'm constantly learning on this topic / new obsession!

You're not alone!

 

[AliK]

I bought mine from their German distributor as they had in stock that day. I don't "think" you can buy direct from NL.

For me the ease of install, Bluetooth convenience, rev limiter, immobiliser and fully programmable curves were the selling points besides the obvious other points.

FYI on 280zx dizzy, I set all in timing (base + mech only) at 34 degs @ 3000rpm. Then when I check with timing light it works out about 17 degrees at 900rpm idle (I.e. Base timing). That means the dizzy is delivering 17 degrees of mech advance. When I connect vac advance at idle it goes to around 28-30 degrees at idle which raises the revs to about 1500-1700 RPMs. So I dial back the idle screws on the carbs to get 1000-1100 rpm idle (as I have a lumpy cam, probably less so than Jon's). At fast idle ie anything over 3000rpm timing light shows around 47 degrees (17 base, 17 mech and between 10-13 vac depending on actual revs).

Sounds eye watering right? Well the mix is lean at idle / fast idle and copes with it without knock / ping. Blip the throttle and the timing light shows that it jumps back to where it should be under base + mech advance. I.e. The moment the vac drops the timing retards. On ECU enabled cars with knock sensors the mix leans out so much that they can advance into the 60s!!!!!!

This is of course all dependent on your cam duration / mods etc. If you consider that a higher duration cam typically has more overlap, you get exhaust gas reversion at low revs / idle and need a bit more timing to get a full burn (as the mix is "dirty").

There is another aspect to consider called the "rate of attack" - which is how quickly the vac canister responds when going from idle to WOT. Which for me was another selling point of the 123 as it has a Manifold Absolute Pressure (MAP) sensor and reacts faster with whatever advance "you" choose to add at any given level of vacuum - as opposed to relying on a spring and diaphragm with a fixed rate or level of advance per mHg of vac.

 

[uk66fastback]

Doesn't work with Apple stuff though - Windoze only ... ! Might have to borrow one of the kids' laptops, or phone ... ! I don't have anything that isn't Apple ...

I keep re-reading the reply above in an effort to understand it ...

 

[AliK]

Doesn't work with Apple stuff though - Windoze only ... ! Might have to borrow one of the kids' laptops, or phone ... ! I don't have anything that isn't Apple ...

Not sure that is strictly correct as I've ONLY used it with my iPhone 6s